The synthesis of 2-, 3-, 4- and 6-O-α-d-glucopyranosyl-d-galactopyranose, and their evaluation as nutritional supplements for pre-term infants
摘要:
Four methods have been screened for the synthesis of some alpha-D-glucopyrano sides, with the recently reported (Mukaiyama) combination of 2,3,4,6-tetra-O-benzyl- alpha-D-glucopyranosyl iodide and triphenylphosphine oxide being the most successful, especially in the diastereoselectivity exhibited. The alpha-D-glueopyranosides so obtained have been deprotected to yield 2-, 3-, 4- and 6-O-alpha-D-glucopyranosyl-D-galactopyranose. Only the last disaccharide showed any hydrolysis by alpha-glycosidases but this success was not emulated by mucosal extracts from the small intestine of the pig. (c) 2007 Elsevier Ltd. All rights reserved.
The synthesis of 2-, 3-, 4- and 6-O-α-d-glucopyranosyl-d-galactopyranose, and their evaluation as nutritional supplements for pre-term infants
摘要:
Four methods have been screened for the synthesis of some alpha-D-glucopyrano sides, with the recently reported (Mukaiyama) combination of 2,3,4,6-tetra-O-benzyl- alpha-D-glucopyranosyl iodide and triphenylphosphine oxide being the most successful, especially in the diastereoselectivity exhibited. The alpha-D-glueopyranosides so obtained have been deprotected to yield 2-, 3-, 4- and 6-O-alpha-D-glucopyranosyl-D-galactopyranose. Only the last disaccharide showed any hydrolysis by alpha-glycosidases but this success was not emulated by mucosal extracts from the small intestine of the pig. (c) 2007 Elsevier Ltd. All rights reserved.
Monoalkylation of Tributyltin Activated Methyl 4,6-<i>O</i>-Benzylidene-α-D-gluco- and -galactopyranosides
作者:Falguni Dasgupta、Per J. Garegg
DOI:10.1055/s-1994-25649
日期:——
Monoalkylation of methyl 4,6-O-benzylidene-α-D-gluco- and galactopyranosides could be carried out in good yields using bis(tributyltin) oxide. Regioselectivity, giving predominant 2-substitution, was excellent in the case of D-glucopyranoside. The ratio of the tin reagent to that of the substrate seems to be critical in determining the yield and the extent of regioselectivity. Alkylation could also be carried out in solvents at a slower rate, using less reagent, but the regioselectivity was lower.
The synthesis of 2-, 3-, 4- and 6-O-α-d-glucopyranosyl-d-galactopyranose, and their evaluation as nutritional supplements for pre-term infants
作者:Peter J. Meloncelli、Tracey M. Williams、Peter E. Hartmann、Robert V. Stick
DOI:10.1016/j.carres.2007.04.022
日期:2007.9
Four methods have been screened for the synthesis of some alpha-D-glucopyrano sides, with the recently reported (Mukaiyama) combination of 2,3,4,6-tetra-O-benzyl- alpha-D-glucopyranosyl iodide and triphenylphosphine oxide being the most successful, especially in the diastereoselectivity exhibited. The alpha-D-glueopyranosides so obtained have been deprotected to yield 2-, 3-, 4- and 6-O-alpha-D-glucopyranosyl-D-galactopyranose. Only the last disaccharide showed any hydrolysis by alpha-glycosidases but this success was not emulated by mucosal extracts from the small intestine of the pig. (c) 2007 Elsevier Ltd. All rights reserved.